Bug 1276901 - prevent null pointer dereference on |nativeKeyEvent|. r=dholbert

MozReview-Commit-ID: J3GtMQDU1Yq

--HG--
extra : rebase_source : 7c4ea962e66be1a084cfc2d765cdee79d726d40e

layout/xul/nsMenuBarListener.cpp

@@ -211,7 +211,8 @@ nsMenuBarListener::KeyPress(nsIDOMEvent* aKeyEvent)
     // the mozaccesskeynotfound event before handling accesskeys.
     WidgetKeyboardEvent* nativeKeyEvent =
       aKeyEvent->WidgetEventPtr()->AsKeyboardEvent();
-    if (nativeKeyEvent && nativeKeyEvent->mAccessKeyForwardedToChild) {
+    if (!nativeKeyEvent ||
+        (nativeKeyEvent && nativeKeyEvent->mAccessKeyForwardedToChild)) {
       return NS_OK;
     }